Studies on the etiology, pathology, and potential therapeutic interventions for Insulin Dependent Diabetes Mellitus (IDDM) have been greatly assisted by the availability of a suitable animal model, the BB-WOR diabetic rat. This model has been difficult to establish and produce. The project objectives of this contract are to continue a centralized and stable source of supply of the BB Wor diabetic rat, a cost-reimbursement system for the distribution of these animals, and the development of genetically homogeneous familial lines with and without the diabetic defect.